Separation of positional isomers on polymeric calix[4]arene-siloxane stationary phases in capillary GC

Abstract

Poly(p-tert-butyldimethoxydipropyloxycalix[4] arene--tetramethyldisiloxane) (TBCX-TMDS) and poly (dimethoxydipropyloxycalix[4]arene-tetramethyldisiloxane) (CX-TMDS), have been prepared and used as stationary phases for isothermal capillary gas chromatographic separations of positional isomers. Retention factors and separation factors for the isomers were measured. The isomers investigated were well-resolved on the two phases. Retention of all the solutes investigated is greater on TBCX-TMDS than on CX-TMDS, probably because of extra dispersive interactions of the solutes with the tert-butyl groups of the phase. Separation factors for closely-eluting isomer pairs are similar on the two phases. This seems to indicate either that the solutes are retained by non-inclusion processes or that if the isomer molecules do enter the cavity of the calixarene, i.e. the solute is retained by inclusion, the tertbutyl groups do not play a role in discriminating between the isomers.

Preparation and characterization of p-tert-butylcalix[8]arene bonded capillaries for open-tubular capillary electrochromatography

“…They can act as receptor molecules of widely varying size for metal cations and organic molecules [1] and after being shown by Gutsche and Mathukrishnan [2] to mimic the action of enzymes, calixarenes have generated a great deal of scientific interest for three decades. Their cup-shaped architecture formed by ordered, oriented and substituted benzene rings enables calixarenes to include small guest molecules of appropriate size and configuration and this attribute has resulted in widely varying applications in ion-selective membranes and electrodes [3][4][5][6] and chromatography [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

Characterization of Calixarene/Ionic Liquid Mixture as Gas Chromatographic Stationary Phase through Thermodynamic Parameters and LSER

“…Owing to high melting points and poor solubility of most unsubstituted calixarenes, it is difficult to coat them onto the internal wall of the capillary column, leading to poor column efficiency and selectivity [9][10][11]. However, the problem can be alleviated by the chemical linking long alkyl chains to the calixarene molecules [12] or attach calixarene molecule directly onto polysiloxanes [13,14].…”

Preparation, characterization and application of a new 25,27‐bis‐[2‐(5‐methylthiadiazole)thioethoxyl]‐26,28‐dihydroxy‐para‐tert‐butyl calix[4]arene stationary phase for HPLC

“…They consist of phenol units linked via methylene bridges and can also form inclusion complexes like the other host supramolecules. The peculiar configurations lead to the formation of typical host-guest interaction between calixarenes and numerous compounds, and result in widely varied applications in ionselective membranes and electrodes [1][2][3][4][5], electrophoresis [6][7][8][9] and chromatography [10][11][12][13][14][15][16][17] and other fields [18][19][20].…”